Use std::once_flag and std::call_once for time constant warnings.

[nkoukpaizan]

Description

This uses std:once_flag and std::call_once to only warn user about the raised time constants once.
This removes the excessive warnings for this known issue.

Proposed changes

• Added static void logTimeConstantWarning() to the relevant header files after TIME_CONSTANT_MINIMUM
• Moved Log::Warning() call to the static method
• Introduced std:once_flag and std::call_once at the call site, when the warning is warranted.

Checklist

• [x ] All tests pass.
• Code compiles cleanly with flags -Wall -Wpedantic -Wconversion -Wextra.
• The new code follows GridKit™ style guidelines.
• There are unit tests for the new code.
• The new code is documented.
• The feature branch is rebased with respect to the target branch.
• [N/A] The CHANGELOG.md has been updated to reflect the changes. If this is a minor PR that is part of a larger fix already included in the file, state so.

Further comments

Will need to better generalize if a similar pattern is needed later.

[lukelowry]

Thank you, I would have struggled with this.

If I run this on two different cases, will it error on the second case if it raises the same warnings?

[nkoukpaizan]

If I run this on two different cases, will it error on the second case if it raises the same warnings?

I don't see a scenario where we'd get an error, and I am not sure I understand the use-case you're describing, so let try these:

• This is thread-safe for contingency analysis, so we get one warning for all contingencies.
• If you have two separate executions of DynamicSimulation, you'll get a warning per executable.

[lukelowry]

If I run this on two different cases, will it error on the second case if it raises the same warnings?

I don't see a scenario where we'd get an error, and I am not sure I understand the use-case you're describing, so let try these:

• This is thread-safe for contingency analysis, so we get one warning for all contingencies.

• If you have two separate executions of DynamicSimulation, you'll get a warning per executable.

Okay that resolves my concern. Thank you sir

[superwhiskers]

this looks fine to me